How to parse conjunctions in natural language processing?
This seems not easy for NLP. I doubt that state-of-the-art NLP tools can reliably determine the correct hierarchical structure of independent clauses. Examples below.

The Berkeley parser gets it basically right in the sense that it can put its late and I'm tired on parallel, and they together on parallel with the weekend. But still not perfect (the weekend should be in the same subtree with It's rather than if its late and I'm tired)



The Stanford parser, which is available in Python (NLTK), incorrectly parsed I\'m tired to the same level of I drink orange juice.